Cars used to have starting handles. For
those who don't remember, they were
shaped like an elongated brace and bit
drill, with a sort of prong on one end that
engaged with a divided nut on the end of
the cam pulley wheel, at the front of the
car's engine.

To use the starting handle, you
inserted
it
via a hole just above the front bumper,
engaged it against the cam and cranked
it,
using a vigorous jerking motion. There
was a knack to it, as you had to pull the
handle towards you after each jerk,
otherwise you risked a mangled arm
once
the engine kicked over.

My idea is to be able to start up your
computer using the same method.
Naturally you would need to fit a little
device to the computer, that engaged
with the hard
drive, but this could have its own car-like
features to add to the theme.

Now, first thing in the morning, when
you
want to boot up your stubborn PC (macs
only have this as a novelty), you open up
your
little tool box, take out the starting
handle, insert it under the fake bumper
fitted to the side or front, and begin
cranking.... cursing and puffing to your
fellow workers "she's always like this on a
Monday" as they do likewise.

After a judicious amount of jerking and
heaving, your PC splutters and farts into
life, its little pretend exhaust emitting a
harmless puff of fake smoke, and its
engine sound effect roaring away until
you
push in the choke, reducing it to its usual
monotonous, electronic hum.

[+] I will try to keep this in mind for whenever I get around to building a computer, though it probably won't go in the first one I build. It could go well with a steampunk or dieselpunk case mod.

I don't actually see any warnings at the linked page relating to the use of the starting handle.

What I don't get is why the receptacle for the starting handle on old cars didn't have an axial cam, sort of like those one-way-drivable security screws, that would safely eject the starting handle once the engine started.

They do. The slots in the dog-clutch that the handle tip engages are curved; when the victim cranks the engine, the rod is pulled further into the receptacle, but if the engine starts that same curve pushes the crank handle out of engagement.

While hand-cranking is practical for small and medium-sized (up to 2.5l ) petrol engines, trying to crank start a cold diesel tractor engine against 27:1 compression is a singularly unrewarding endeavour.

It should be borne in mind that, as with aircraft, hand-starting bites if you get it wrong.

For a computer case concept I'm thinking about, I've just realized it would be convenient to have a carrying handle on top that can be detached and stowed when the computer isn't being carried. I'm now trying to imagine how that handle could be designed such that it could double as a starting handle once the computer is set down and the handle is detached from its carrying position.

Long ago, back in the 1990's, I regularly had to
crank-start my car as the starter motor had an intermittent fault. Also there was a problem with the petrol pump which would mean that it would sometimes stop running. If both faults occurred at the same time I'd have to jump out, while stationary in traffic, and crank-start the car, to the amusement of other motorists...